This proposal is based on the model of a transplantable murine tumor which produces large amounts of an extracellular basement membrane matrix. Collagenous and noncollagenous proteins comprising this matrix can be solubilized without resorting to proteolytic or chemical degradation. These proteins will be purified and characterized with respect to their composition and subunit structure, physical properties, fragment patterns and partial amino acid sequences. Antisera will be raised against purified protein component and used for immunochemical studies and for the preparation of specific antibody reagents. It is intended to localize several antigenic determinants within these molecules and to determine their amino acid sequence. Methods established in the immunological studies will be used to determine the tissue distribution of these proteins, to study their biosynthesis in cell cultures and to characterize the interaction between these components. These antibodies will also be used to study changes in tissue antigens and the occurrence of these antigens in serum and urine of patients with clinical disorders involving basement membranes (diabetes, glomerulonephritis, scleroderma). Assays will be developed to characterize autoantibodies reacting with basement membrane in human patients (Goodpasture's syndrome) and in mice immunized with basement membrane proteins.